[hwillis]

Powertrain is technically correct, since only the flywheel/torque converter/transmission/driveshaft (and occasionally the differential) are really replaced from a drivetrain.

The battery has represented ~80% of an electric powertrain's cost, so it's a reasonable proxy for replacing most of the powertrain. Even parts that aren't fully replaced, like the heater core, A/C and radiator are made significantly cheaper. It's very much an estimate, but it isn't inaccurate.

Recently it's becoming less representative. Drive stages (electronics) are getting more exotic and expensive as manufacturers recognize the value in them, and motors are probably going to continue using limited amounts of neodymium magnets. And of course, batteries have become far cheaper. Personally I can't wait- I want more focus to be on the motors and drivers, which are way more accessible from an aftermarket perspective. It takes tens or hundreds of millions to get into battery manufacturing, but only a few hundred thousand to get into making world-class motors or electronics. Crate engines for EVs are just waiting on the demand (and a friendly nod from manufacturers).